The crystal state of a compound may be important when the compound is used for pharmaceutical purposes. Compared with an amorphous solid, the solid physical properties of a crystalline compound may change, which may affect its suitability for pharmaceutical use. For example, a particular crystalline compound may overcome the disadvantage of other solid forms of the compound that readily absorb moisture (e.g., high hygroscopicity). For an ionic drug substance, high hygroscopicity may diminish the drug product's stability profile by a host of mechanisms, as the drug substance may have a propensity to absorb water. Water that is absorbed from the environment (packaging materials, exposure to air, or in the case of formulated products, from other materials), may lead to degradation products and/or impurities in a drug product or add to the cost of manufacturing the drug product with acceptably low levels of water.
One compound that can be obtained in amorphous or various crystalline salt forms is (2S,3S,5R)-3-((1H-1,2,3-triazol-1-yl)methyl)-3-methyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid 4,4-dioxide, or tazobactam. There is a need for solid forms of tazobactam with reduced hygroscopicity for use in drug substance and drug product development.